This non-provisional application claims priority under 35 U.S.C. § 119(a) on Korean Patent Application No. 2003-47731 filed on Jul. 14, 2003, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to a siloxane-based resin and an interlayer insulating film for a semiconductor device formed using the same. More specifically, the present invention relates to a siloxane-based resin containing germanium and a resinous film useful as an insulating film between interconnecting layers of a semiconductor device.
2. Description of the Related Art
As the circuit density of multilevel integrated circuit devices increases, the size feature of a semiconductor device is constantly required to be reduced. The chief obstacle to the feature of size reduction of a semiconductor device is the R(resistance)×C(capacitance) delay due to crosstalk between interconnecting layers. A solution to this problem is to lower the dielectric constant of interlayer insulating films so as to decrease the RXC delay as much as possible. So, there have been various attempts to provide an insulating film having a low dielectric constant.
Conventionally, in the field of semiconductor devices, interlayer insulating films have been formed by a CVD (chemical vapor deposition) method using SiO2 having a dielectric constant of 4.0. However, U.S. Pat. Nos. 3,615,272; 4,399,266; 4,756,977 and 4,999,397 disclose the formation of insulating films by the SOD (spin on deposition) method using polysilsesquioxanes having dielectric constants of 2.5–3.1 as well as good planarization properties.
Hydrogen silsesquioxanes as well as preparation methods thereof are well known in the art. For example, U.S. Pat. No. 3,615,272 discloses a method of preparing a completely condensed, soluble hydrogen silsesquioxane resin, which comprises the steps of condensing trichlorosilanes in a sulfuric acid medium and washing the resulting resin with water or aqueous sulfuric acid. Also, U.S. Pat. No. 5,010,159 discloses a method of synthesizing a soluble condensed hydrogen silsesquioxane resin, which comprises the steps of hydrolyzing hydrosilanes in an arylsulfuric acid hydrate-containing hydrolysis medium and contacting the resulting resin with a neutralizing agent. U.S. Pat. No. 6,232,424 describes a highly soluble silicon resin composition having excellent solution stability, which is prepared by hydrolyzing and polycondensing tetraalkoxysilane, organosilane and organotrialkoxysilane monomers in the presence of water and a catalyst. U.S. Pat. No. 6,000,339 describes that a silica-based compound is useful for improving the resistance to oxygen plasma and physical properties as well as the thickness of a coating film, which can be obtained through reacting a monomer selected from the group consisting of alkoxysilane, fluorine-containing alkoxysilane and alkylalkoxysilane with a titanium- or zirconium-alkoxide compound in the presence of water and a catalyst. U.S. Pat. No. 5,853,808 discloses that siloxane and silsesquioxane polymers useful for forming a SiO2-rich ceramic coating can be obtained from hydrolysis and polycondensation of organosilanes having a β-substituted alkyl group. Meanwhile, EP 0 997 497 A1 discloses that hydrolyzation and polycondensation of a certain combination of alkoxysilanes including mono-, di-, tri-, tetraalkoxysilane and trialkoxysilane dimers can provide resinous materials for insulating films.